1. Field of the Invention
This invention relates to an inverter generator, particularly to an inverter generator equipped with a generator unit driven by an internal combustion engine, in which speed of the engine is controlled in accordance with load.
2. Description of the Related Art
One well-known inverter generator once converts the alternating current outputted by an engine-driven generator unit to direct current and then converts the direct current into alternating current of a predetermined frequency (utility frequency) by driving switching elements with a PWM signal generated using a reference sine wave of the desired output voltage waveform and a carrier. Examples of such an inverter generator can be found in Japanese Laid-Open Patent Application Nos. H11(1999)-308896 ('896) and H4(1992)-355672 ('672).
The reference '896 teaches a technique to detect a turn-on angle of a thyristor and control engine speed so that the detected angle becomes a desired turn-on angle.